Hydrogen is attractive as a fuel or additive for internal combustion engines because hydrogen as a fuel source can significantly reduce air pollution and can also serve as an alternative energy source to gasoline. See Mishchenko, et al., Proc. VII World Hydrogen Energy Conference, Vol. 3 (1988), Belogub, et al., Int. J. Hydrogen Energy, Vol. 16, 423 (1991), Varde, et al., Hydrogen Energy Progress V, Vol. 4 (1984), Feucht, et al., Int. J. Hydrogen Energy, Vol 13, 243 (1988), Chuveliov, et al., In: Hydrogen Energy and Power Generation, T. Nejat Veziroglu, Ed., Nova Science Publisher, New York, N.Y. (1991), Das, Int. J. Hydrogen Energy, Vol 16, 765 (1991). Moreover, engine efficiency can be 10-50% higher when running on hydrogen as compared with a gasoline engine. Prior art systems contemplated either storing hydrogen on-board or generating it on board. On-board storage requires high pressure vessels, cryogenic containers if the hydrogen is to be stored as a compressed gas or liquid, or large getter volumes and weights if the hydrogen is to be stored as a hydride. Moreover, the refill time for hydrogen is substantially longer than that for gasoline when the hydrogen is to be stored on-board.
As to the on-board production of hydrogen, several approaches have been disclosed in the prior art. For example, U.S. Pat. No. 5,143,025 to Munday discloses the use of electrolysis to separate water into hydrogen and oxygen and introducing the hydrogen into an internal combustion engine. In U.S. Pat. No. 5,159,900 to Dammann, hydrogen gas is produced by water interaction with solid carbon. Electrical current is passed between the carbon electrodes causing the electrodes to burn and oxidize to form carbon monoxide and hydrogen. U.S. Pat. No. 5,207,185 to Greiner et al. discloses a burner which utilizes a portion of the hydrocarbon fuel to reform another portion to produce hydrogen. The hydrogen is then mixed with the hydrocarbon fuel for introduction into an internal combustion engine.
Another system diverts a fraction of the gasoline from the flow path to the engine and is passed through a thermal converter and steam reformed to yield hydrogen-rich gas. See, Breshears, et al., Proc. of EPA 1st Symposium on Low Pollution Power Systems Development, 268 (1973). We note that the authors state that this system would not be practical to generate hydrogen as the sole fuel for an engine. Yet another system of this type uses partial oxidation in a catalytic converter to produce hydrogen rich gas. See Houseman, et al., Proc. 3rd World Hydrogen Energy Conf., 949 (1980). This system requires carefully controlled catalytic action and temperature range and has limitations for startup and transient response.
U.S. Pat. Nos. 5,425,332 and 5,437,250, both to Rabinovich et al., disclose plasmatron-internal combustion engine systems. The systems disclosed include a source of hydrocarbon fuel which is supplied to a plasmatron which reforms the fuel into a hydrogen-rich gas. Plasmatrons heat an electrically conducting gas either by an arc discharge or by a high frequency inductive or microwave discharge. An internal combustion engine is connected to receive the hydrogen-rich gas from the plasmatron. While these systems are significant improvements over the prior art, it would be desirable to provide systems that are capable of rapid response for instantaneously providing hydrogen-rich gas, reducing pollutants during startup and allowing use of hydrogen-rich gas during typical load changes. The entire contents of both U.S. Pat. Nos. 5,425,332 and 5,437,250 are incorporated herein by reference.